Conventionally, when engaged in a work necessary to achieve the object as described above, the clinician places a biopsy specimen into a flat cassette with a lid made of an opaque porous plate, closes the lid, puts the cassette into a capsule where an antiseptic agent has been placed that prevents the specimen from degrading, and sends the capsule to a pathological laboratory for inspection.
In the pathological laboratory, the tester takes out the embedding cassette from the capsule, opens the lid of the cassette, and compares the biopsy specimen therein with the description on a bill attached to the specimen, to confirm that the specimen properly coincides with the description. Then, he places again the specimen into the cassette, puts it in a vessel containing alcohol or xylene, and submits it to processes comprising dehydration, removal of fat, removal of alcohol, and immersing it in an embedding agent consisting of paraffin or a resin in succession.
Then, the tester opens the lid of the embedding container, picks up the biopsy specimen directly with a pair of forceps, and transfers it to another embedding plate prepared in advance. He places the bottom of the embedding cassette which is made of a porous plate above the biopsy specimen placed on the embedding plate, with some spacing there between, and pours an embedding agent consisting of molten paraffin or resin over the bottom, to embed the biopsy specimen together with a part of the embedding cassette with the embedding agent. In this state, the embedding agent is allowed to cool so that the biopsy specimen embedded together with the part of the embedding cassette in the embedding agent is hardened to form an embedded block.
Then, the pathologist cuts the biopsy specimen kept in the embedded block with a microtome together with the embedding agent, into thin sections, and examines them with a microscope.
The above described processes employing the conventional embedding cassette have following problems which remain to be improved.
Firstly, during embedding operation, the biopsy specimen is picked up directly with forceps before it is transferred to the embedding plate. This operation may distort the specimen locally by pressure, and inflict damages thereupon, which may interfere with proper treatment of the specimen for laboratory inspection.
Secondarily, if a plurality of specimens are placed in the embedding cassette in the order of sampling or according to sampled sites, they may be placed in a different arrangement from the original one by accident when they are transferred to a separate embedding plate. Further, while they are transferred to a separate embedding plate, they may be wrongly intermingled with biopsy specimens from a different embedding cassette, or some of them may be exchanged for wrong specimens from a different cassette. If such wrong operations happen, they would bring a grave effect on the results of microscopic inspection which takes place following the transference.
Thirdly, after being embedded, a part of the biopsy specimen necessary for inspection is cut by the pathologist with a microtome into thin sections which are then observed by microscopy. However, as the technician who is responsible for embedding the biopsy specimen and the pathologist are generally different persons, the technician finds it difficult to locate the part of the specimen which the pathologist would desire to inspect, and thus finds it difficult to place the biopsy specimen on the embedding plate so as to allow the pathologist to cut the desired part thereof with a microtome. In short, with the conventional method it is very difficult for the pathologist to cut rightly the part of the specimen necessary for inspection into thin sections.
Fourthly, each time the tester compares the biopsy specimen with the description on a bill attached thereto in the embedding cassette, he must open the lid of the cassette. This confirmation work requires a considerable time. In addition, when the lid is opened, the biopsy specimen may fall by accident from the cassette.
Fifthly, as the embedding cassette is partly composed of a porous plate, the biopsy specimen may be lost by flowing through a pore, when it is sufficiently small to pass through the pore.
As the sixth problem, the embedded block requires a certain thickness because it must withstand the pressure from the cutting edge of a microtome, when cut into thin sections. In a big hospital or laboratory a vast number of waste blocks are produced, and to make the most of the space necessary for their storage, they are laid one over the other. For them to be laid one over the other neatly, they should be made as thin as possible.
The first object of this invention is to dispense with the use of forceps or other mechanical means which, in conventional methods, are used to transfer a biopsy specimen to an embedding plate, and thereby to protect the specimen from distortion by pressure which may lead to local damages.
The second object is to prevent a plurality of biopsy specimens which are placed properly in an embedding cassette from being placed in a different arrangement from the original one when they are transferred to a separate embedding plate, or from being confounded with other wrong biopsy specimens.
The third object is to permit the pathologist to cut properly a part of biopsy specimen necessary for inspection into thin sections, and thereby to make a proper inspection on them.
The fourth object is to facilitate the work involved in conforming that the biopsy specimen placed in an embedding cassette corresponds rightly with the description on a bill attached to the specimen, and further to prevent the specimen from being lost by accident during this confirmation work.
The fifth object is to prevent the biopsy specimen from flowing through a pore of the porous plate of an embedding cassette.
The sixth object is to reduce the thickness of an embedded block while maintaining its mechanical strength.